Volumetric imaging of cardiac current sources using Lp-norm regularization

Computational cardiac current source imaging aim to mathematically reconstruct current source activities from noninvasive voltage data sensed on the body-surface. However, the progress in this field is hindered by the ill-posedness and the lack of a unique solution of the reconstruction problem. Common L2 and L1-norm regularization tend to produce a solution that is either too diffused or too scattered to reflect the complex spatial structure of current source distribution in the heart. In this work, we propose a general regularization with Lp-norm (1 <; p <; 2) constraint to bridge the gap and balance between an overly-smeared and overly-focal solution in cardiac source reconstruction. In a set of phantom experiments, we demonstrate the superiority of the proposed Lp-norm method over its L1 and L2 counterparts in imaging cardiac current sources with increasing extents. Through computer-simulated as well as real-data experiments, we further demonstrate the feasibility of the proposed method in imaging the complex structure of current sources activity along the infarct border. This ability to preserve the spatial structure of source distribution is important for revealing the potential disruption to the normal current flow in the heart.